Fluid gun



A. B. CUMNER Nov. 5, 1929.

FLUID GUN Filed 06T.. 25, 1927 Il lll-H WITNES ORNEYS.y

Patented Nov. 5, 1929 i UNITED STATES" PATENT OFFICEv ARTHUR B. camina, or NEW Yonx, N. Y.

man) GUN `f Application led October 25, 192,7. Serial No. 228,550.

This invention relates to fluid or grease guns useful, for example, in connection with systems for lubricating the vvarious bearings associated with the running gear of automobiles; and, more specifically speaking, it is concerned with grease guns particularly adapted to automobile service stations.

In the generality of power-operated oneman outts commonly in use they all multiply the pressure on the lubricant on the dolly and transmit the lubricant atthe high pressure-usually ranging from 2000 lbs. to 5000 lbs. per square inclu-through flexible tubing averaging five feet in length. Flexible tubing having to carry such high pressures is invariably short lived, while the use of solid tubing incorporating flexible joints is objectonable in that such joints are decidedly limited in angle of operation and consequently easily broken.

My present invention has for its primary object to provide a fluid gun in which the high pressure is developed closely proximate to, or right at, the point of'extrusion directly into the bearing or oil ducts to be cleansed; or, in other words, I fundamentally aim to eliminate the necessity for use of lengthyj conductive means, intermediate the gun and point of application, that has heretofore been subject to pressure tendin to disrupt the same or create leaks at the joints therein.

My present invention is further directed toward affording a structurally simple and easily operable fluid or grease gun capable of utilizing compressed air-or any other suitable pressure medium-in determining successive delivery of measured charges of the lubricant at pressures sufficiently high to overcome theresistance of, .and to displace,

any clogging matter likely to be held by rust or otherwise in the ducts of bearings being oiled.

Still further, I aim to provide a grease gun incorporating a trigger-controlled taper-plug valve with only a single air passage, and in utilizing a portion of said passage for bothI intake and exhaust purposes.

Other objects and advantages of this invention will be apparent from the detailed description which follows of the typical embodiment shown in the accompanying drawings; while the subjoined claims serve to define the features of novelty.

Fig. II is a detail section taken locally,l u

as indicated by the arrowsII-II in Fig. I.

From these illustrations, it will be seen that the device is suitably configured for ease in grasping, and embodies a part 3 simulating the stock of a gun, together with a laterallyprojecting barrel portion comprising a cylin- G5 der 4, 'and an axiall -aligned dome-like section 5 having an applicator nipple 6 forming an extension' of the diametrically reduced forward neck portion 7 of said section 5. The inner end of the cylinder 4 is re- -70 ceived within a recess 8 in the stock 3, while its forward end is closed b a cap-like fitting 9, which is circumferentia ly extended at 10 to afford a seat for a projecting base flange 11 on the dome section 5, the several parts aforesaid being secured together by a number of longitudinally-disposed tie-bolts 12, one only being visible in the drawings.

lVithin the cylinder 4 is a piston 13, fitted with a renewable cup gasket 14, which is under the influence of a helical spring 15, that y serves to move said iston from the position shown, by virture of) a relief port 16 in the stock 3, as later on set forth. Fluid pressure medium (preferably compressed air) for ac- S5 tuating the piston 13 is conducted to the cylinder 4 via a duct 17 that extends axially through the bridging portion or obtuse-angled arch section 18 of the stock 3, and downward through the vertical or grasp portion 19 of 90 said stock to the bottom end of the latter where a supply pipe is connected through the ymedium of a conventional attaching nipple 21; all as clearly shown in Fig. I. Exhaust from the cylinder 4 is by Way of the forward 95 portion 17 of the duct 17 and relief port 16,

when the control valve 22 is released; as hereafter explained. Actuation of the piston 13 is effected by the control valve 22 just referred to, and it will be noted the same is 10 of the outer end of the fitting 9, asshown in .into said nipple,

of the three-way taper-plug variety. To this end, the bridging portion 18 of the stock 3, is medially enlarged at 23 and bored to receive a screw-threaded sleeve 24 that serves as a seat for the taper plug valve 22; said. valve being frictionally influenced, by a yspring 25 under compression, held thereagainst by a cupped cap 26 with capacity of adjustment, in an obvious manner.

The valve 22 is provided with an axial extension 27 to which a finger trigger 28 is keyed by means of a Cotter-pin 29, and said trigger is normally held in a position with the heel portion 30 thereof abutting aiiat 31 on the underside of the bridging section 18, under the action of a retractile spring 32, conveniently hooked to the trigger at 33 at one end and to a screw 34 threaded into the perimetric surface of the stock about the cylinder nd receiving recess 8, hereinbefore referred Referring again to the piston 13 it will be noted that the same is secured to a rod 35 operating as a plunger within a tube 36 which is passed through the diametricallyreduced neck 7 of the dome-section 5 an screwed into a central boss 37 of the cap-like fitting 9. `The tube 36 is in communication with the hollow ofthe dome-section 5 through radial ports 38 for capacity to receive ui or semi-fluid lubricant conducted to the device under pressure from a suitable source of supply, not shown, through a pipe 39. This pipe 39 follows the `rounded portion 40 of the stock 3 and takes into the inner side of Fig. I. The outer end of the tube 36 projects somewhat beyond the neck 7 of the section 5 and'is screwthreaded to take the nipple 6. On its interior, the nipple 6 provides a seat 41 for a ball valve 42 that is. urged' inward by a spring 43 whereof the pressure is adjustable by means cf a screw sleeve 44 threaded axially and the adjustment ixable by direct appllcation of a standardized iiexible adapter coupling 45 of the kind ordinarily used in this art. Attention is drawn to the internal and external screw-threading the nipple 6, whereby the device may be directly applied to suitable parts needing purging and lubrication, as. well .as the convenience afforded for attachment of diierent sized adapters 45.

Attention is again directed to the threeway taper-plug control valve 22, which is provided with a diametric passage 46, and a ort 47 at right angles thereto but slightly c set relative to the axis of said valve, as clearly seen in Fig. I. 'It is to be further noted that `when tie parts are in the operative position shown that the passage 46 in the plug valve 22 affords free communication by way of the duct 17 -17 and that the relief port 16 is closed. n the other hand, when the trigger 28 isreleased, the offset port 47 is Aturned into alignment with the duct section 17', with the immediately proximateor shorterportion of the passage 46 open to the relief 16, and the duct 17 shut-off.

In operation, the return stroke of the plunger rod 33 under the action ofcthe spring 15 iniiuencing the piston 13, creates a vacuum in the tube 36 thereby facilitating flow thereinto, through the radial ports 38, of the lubricant conducted to the dome-section 5, under pressure, by way of the supply pipe 39. The

i tube 36 thus acts as a measuring chamber to actuation of the trigger a fixed quantity or With the tube 36 pulled to the illusthereby imparting d plunger rod 35 is carried forward to displace the charge of lubricant from the tube 36 past the ball valve 42 and to expel such charge throu h the nipple 6 and adapter attachment ow, it will be noted that by virtue of the very great difference in the areas of the piston 13 and the plunger rod 35, the pressure of extrusion is correspondingly multiplied. With the parts proportioned and 'assembled approximately as shown, it is possible to secure, with compressed air at pressures ordinarily available in service station equipment, delivery of lubricant with ample force at the point of application to insure dislodgment of any clogging matter tending to resist penetration of the bearings being oiled.

As a consequence of provision of the finger trigger 28 and taper plug control valve 22, it will be apparent my novel grease gun is manipulated with the greatest ease, while said device may be readily taken apart either for periodic cleaning or replacement of any worn parts, when required, after extensive use in ractice.

Although I have described my invention as articularly useful for dispensing lubrieating oil or grease, it may be employed. with equal advantages in handling of other liquid or semi-solid substances.

Having thus described my invention I claim:

1. In a iiuid gun comprising adome-section chamber having an intercommunicatin axial tube` for receiving and measuring a efinite charge of the fluid, a plunger operating in said tube, an axially aligned actuating cylinder connected to the aforesaid chamber, and a spring return piston in said cylinder of considerably greater area than the lunger an direct connected thereto, the com ination of a p stock having an inlet duct through whichfluent motive medium is conducted to the actuatin cylinder, said duct including an arche portion having a medially ositloned enlargement with the forward sectlonof said duct serving as an exhaust qutlet, and a trigger vac'tuable taper plug valve seating in said enlargement to control flow and exhaust of motive-medium therethrough.

2.`- In a fluid n of the type described, the combination ogn a stock member having a pressure medium inlet duct includin an angularly arched portion with a media ly positioned intersectmg enlargement, one part of said arched ortion serving both asa flow inlet and ex aust connection from an actuating cylinder clamped to said stock and having a spring return piston with an axial plunger, a trigger-actua le taper-plug threeway valve seating in the enlargementaforesaid, and a dome-section with a concentric interconnecting tube-for receiving and measuring fluid-axially aligned with and attached to the actuating cylinder and under control of the plunger aforesaid, whereby a fixed quantity of the fluid charge is expelled under multiplied pressure at each actuation of the gun.

` 3. In a fluid n of the type described, the combination og a stock member having a pressure-medium inlet duct including an obtuse-angled section with a mediall Ppositioned intersecting enlargement, the fbrward half of said section serving both as a liow inlet and exhaust outlet from an actuating cylinder clamped to said stock and having a spring return piston with an axial plunger, a spring influenced trigger-actuable threeway valve seating in the enlargement aforesaid by aid of a removable sleeve, and a fluidreceivmg dome including an axial measuring tube connecting with said chamber by radial ports, said measuring tube being controlled by the plun er aforesaid to effect expulsion of a fixed1 uid charge under multiplied pressure with each actuation of the gun.

4. In a fluid gun of the t ing a spring return piston with an axialv plunger,` a removable sleeve in the enlargement aforesaid providing a seat for a taperplug three-way valve, a cupped-cap and spring adjustable to maintain said valve frictionally seated, a spring .influenced trigger t for imparting asu stantially quarter turn to the valve, and a fluid-receiving dome including an axial measuring tube connecting with said chamber by radlal ports, for the purpose specified.

ARTHUR B. CUMNER e described, the combination of a stock mem er having a presl an obtuse- 

